Manufacture of phosphate compounds for manures and fertilizers.



UNITED STAS IPA IIFICEO ALEXANDER DICKSON, 0F DUBLIN, IRELAND.

MANUFACTURE OF PHOSPHATE GUI/[POUNDS FOR MANURES AND FERTILIZERS.

No Drawing.

To all whom it may concern Be it known that I, ALEXANDER DIOKSON, a subject of His Majesty the King of England, residing at 15 Parliament street, in the city and county of Dublin, Ireland, have invented certain new and useful Improvements in the Manufacture of Phosphate Compounds for Manures and Fertilizers, of which the following is a specification.

This invention relates to improvements in the manufacture of manures and fertilizers containing phosphate compounds and it has particular reference to the method of producing available phosphates by combining with the recovered solids from sewage waste and the like. 7

As is well lmown the precipitated and separated solids of sewage known as sludge contain a small percentage of organic acids. These acids become concentrated during the process of desiccation and if, as according to the present invention, a quantity of insoluble phosphate such as phosphate rock be added to the sludge before desiccation, the before mentioned concentrated acids will effect an alteration in the character of the phosphate and produce a material containing phosphate in a form available for plant life. Suitable salts such as sulfate of potash, sulfate of soda, sulfate of magnesia may be added to enrich the resulting product.

The desiccation and chemical reaction is preferably efiected at such a temperature as will not destroy the organic constituents of the sludge and in practice temperatures from 400 to 600 Fahr. have been found effective. In conjunctionwith the organic contents of the sludge a fertilizer is then obtained containing nitrogen, potash, and available phosphates together with a considerable quantity of organic matterof the nature of humus.

In practice good results may be obtained by employing one ton of sewage sludge containing about 80% of moisture which is Specification of Letters Patent.

Patented Mar. 16, rain.

Application filed September 12, 1914. Serial No. 861,450.

mixed with about 3 cwt. of finely ground phosphate. The mass is then passed in the wet condition to a drier where it is desiccated.

I am aware that it has previously been to secure by Letters Patent of the United States is p 1. In a manure or fertilizer the method of producing available phosphates from insoluble phosphates according to which the insoluble phosphates are added to the recovered solids from sewage waste and the like and the mass is then subjected to desiccation efiected at such a temperature as will not destroy the organic constituents of the sludge whereby to concentrate the acids to such degree as to re-aot upon the phosphates and render such phosphates available for the purpose described.

2. In a manure or fertilizer the method of producing available phosphates from insolu ble phosphates according to which the insoluble phosphates are added to the recovered solids from sewage waste and the like and the mass is then subjected to desiccation efl'ected in a temperature between 400 and 600 Fr. substantially as and for the purpose described.

In testimony whereof I have, signed this specification in the presence of two subscribing witnesses.

' ALEXANDER DICKSON. Witnesses: i

K. SHANAGHED, 

